An executive at a salvage firm says BP interfered with critical efforts to lower an undersea robot to try to close the device that failed to stop the massive Gulf of Mexico oil spill.

Doug Martin, president of Smit Salvage Americas, says the oil giant was concerned about heat buildup from the burning Deepwater Horizon rig. Martin's company was hired to help try to save the rig after it exploded.

Martin told a federal investigative panel Monday that in the hours after the April 20 disaster, he thought it was important to quickly get the robot into the water so engineers could choke off the oil.

But, Martin said, BP officials discussed calculating how the heat from the fire would impact the boat that was to launch the robot. He said he believed that it was a waste of time.